The research aimed at the applications of organic thin film elements in electronics is actively being carried out whereas the development research organic devices such as field-effect transistor (FET: Field Effect Transistor), organic electroluminescent elements (EL; Electro Luminescence, hereafter also referred to as organic EL elements), a solar battery and like is also being promoted as the organic thin film elements. The organic FET (Field Effect Transistor) has received widespread attention because the characteristic of the organic FET surpasses the characteristic of an amorphous silicon FET. The organic EL elements have received widespread attention and have put to practical use since they essentially comprise of characteristics of high intensity display for light emission surpassing those of liquid crystals.
The conventional method of evaluation of general organic thin film elements is carried out by the evaluation of the electrical conductivity property, or the evaluation of the crystal structure using by X rays. X ray diffraction which uses the phenomenon of X ray diffraction by the crystal lattice is a representative example of an evaluation method using X rays. The X ray is an electromagnetic wave with short wavelength wherein it is a technique which determines the alignment of the elements inside the crystal by analyzing the results of diffraction. However, when the X rays are applied on the macro size sample, the X rays penetrate only a few hundred mm of its surface. Therefore, the X ray diffraction method is an evaluation method restricted to the purpose of examining the crystal structure limited to the surface of its material. As described, the state and the electrical conduction mechanism of the electric charge carrier of the organic surface layer could not be ascertained by the conventionally used macro evaluation method.
In contrast, the evaluation method of micro phenomenon involves focusing on the unpaired electron which exists in the magnetic material, observing the spin state and directly evaluating the electrical conduction mechanism. The electron has a spin property, and since it consists of the angular momentum and the magnetic moment, if the magnetic field is added, the energy state of the spin of the unpaired electron is split into two levels. Using this phenomenon, a resonance phenomenon is observed in the sample comprising of an unpaired electron in the material, due to the absorption of microwaves in accordance with the transition of spin of the unpaired electron, in the magnetic field of a few thousand Gauss.
Therefore, the electron spin condition of the unpaired electron can be observed by trapping the several electric charge carriers after keeping the electric charge carrier in the material, in the stationary state. Owing to these reasons, the results of measurement in the organic field effect device which can use the insulating layer in which the electric charge carriers can be trapped are reported. For example, the molecular assembly structure in the device and the electron state of the electric charge carrier which has filled the electrical field in the structure have been determined by the microscopic evaluation using the observation of electron spin state in MIS (Metal Insulator Semiconductor) interface, TFT (Thin Film Transistor) or FET interface.
The inventors, by using a method which directly evaluates the electron spin, observed the state of the electric charge carrier accumulated in the MIS interface and FET interface as the organic thin film using the insulating layer, and evaluated the spatial extent of electrical charge having a deep correlation with the characteristics of the device and the molecular orientation of the organic molecule (refer to Non-Patent Literature 1˜3 and the like).
On the other hand, it is difficult to understand the accumulation of electric charge carrier in the organic thin film solar battery which does not use the insulating layer, and besides, it is essential to further illuminate the light for the organic thin film solar battery wherein the electron spin in the organic thin film solar battery structure is not evaluated. The method of evaluation comprising the change in the quality of material due to the deterioration of the material for painting the automobiles is an example reported as an usage example of electron spin resonance phenomenon for the evaluation of an organic macromolecule compound or an organic material formed from an organic macromolecule which combines an organic compound and an inorganic compound (Refer to Patent document 1 and the like).
The cases which make use of the electron spin resonance phenomenon in the development of the organic EL elements, for the evaluation of the substrate of the organic EL are illustrated. Here, the substrate and the electrode layer formed on the substrate in the pattern shape are formed so as to cover the electrode layer, the photo catalyst containing layer is exposed to the ultraviolet rays and the electron spin resonance spectral is measured for the substrate for organic EL elements comprising a photo catalyst and a binder wherein the photo catalyst containing layer changes the wetting using the action of photo catalyst in accordance with the energy radiation (Refer to Patent document 2 and the like).
Further, the example is of an organic thin film solar battery which achieves high efficiency by focusing on the unpaired electrons. It is an organic thin film solar battery in which the hole retrieval layer comprises a low molecular compound containing a conductive macromolecular material and an unpaired electron, for the organic thin film solar battery comprising a first electrode later formed on the substrate, a hole retrieval layer, a photoelectric conversion layer and a second electrode layer. The focus is on the unpaired electron however the electron spin is not measured. The hole migration of the conductive polymer is smoothly carried out and the incident photon-to-current conversion efficiency is improved. (Refer to Patent Document 3 and the like)
Further, the cases have been proposed in which two sets of sample chamber formed from the sample and the cavity resonator are used for the time-resolved electron spin resonance phenomenon measurement method and the device (Refer to Patent Document 4 and the like).
There is another publication of application as for the organic thin film solar cell battery and the coating solution for forming the photoelectric conversion layer (see Patent document 5 and the like).    Non-Patent Document 1: K. Marumoto et al. “Electron Spin Resonance of Field Induced Polarons in Regioregular Poly(3-alkylthiophene) Using Metal Insulator Semiconductor Diode-Structures”, Journal of the Physical Society of Japan 74(11) (2005) 3066-3076    Non-Patent Document 2: K. Marumoto et al. “Spatial Extent of Wave Functions of Gate Induced Hole Carriers in Pentacene Field Effect Devices as Investigated by Electron Spin Resonance”, Physical Review Letters 97(25) (2006) 256603-1-256603-4    Non-Patent Document 3: K. Marumoto et al. “Electron Spin Resonance Observation of Gate Induced Ambipolar Charge Carriers in Organic Devices”, Japanese Journal of Applied Physics 46(48) (2007) L1191-L1193    Patent document 1: Japanese Unexamined Patent Application Publication No. H9-038078    Patent document 2: Japanese Unexamined Patent Application Publication No. 2007-48529    Patent document 3: Japanese Unexamined Patent Application Publication No. 2006-278584    Patent document 4: Japanese Unexamined Patent Application Publication No. 2002-257759    Patent document 5: Japanese Unexamined Patent Application Publication No. 2008-91467